A total of 1672 WIHS women and 1265 MACS men reported using ART at 22,250 study visits occurring between January 1, 2001 and December 31, 2007. WIHS women were predominantly younger Black women, with lower educational attainment, lower household incomes, and greater use of public health medical payors as compared to MACS men (). MACS men had a higher mean CD4 count, a lower mean log10 HIV-1 RNA, and did not report a CDC-defined AIDS diagnosis as frequently as WIHS women, when they entered our study.
Baseline characteristics of participants reporting ART use, the Women's Interagency HIV Study (WIHS) and the Multicenter AIDS Cohort Study (MACS), 2001–2007
Guideline inconsistent ART was reported by 463 participants (16%) at n=922 study visits (4%) from 2001–07. Of the study visits where participants reported using guideline inconsistent ART many were subpotent regimens (e.g. mono/dual therapy; 67% WIHS; 59% MACS; 63% combined). Some participants reported toxic combinations (e.g. didanosine + stavudine; 17% WIHS; 28% MACS; 22% combined) at their visits. Fewer participants reported adversely interacting combinations (e.g. zidovudine + stavudine; 15% WIHS; 12% MACS; 14% combined) or combinations which were otherwise not recommended (e.g. enfuvirtide for treatment naïve patients; <1% for WIHS, MACS and combined) during their study visits. The most frequently reported guideline-inconsistent regimens included use of didanosine plus stavudine after November 2003 (21% combined), use of dual drug therapy between July 2003-October 2004 (20% combined), use of saquinavir as the sole PI after the year 2000 (14% combined), and ART monotherapy used during 2001–2006 (12% combined). illustrates the prevalence of guideline-inconsistent regimens by calendar year and cohort. The proportion of visits at which participants reported using guideline inconsistent ART remained stable over the study period, ranging from 3–8% (p for trend = 0.70). The prevalence of guideline-inconsistent ART peaked in 2004, likely due to the influx of four new antiretroviral agents in 2003, and two updates to the DHHS guidelines issued during 2004. There was no linear trend over time in the prevalence of guideline inconsistent ART for WIHS (p = 0.43) or MACS participants (p = 0.92).
Prevalence of study visits where participants reported using guideline inconsistent ART regimens, by gender and calendar year
Potential factors that may influence the receipt of guideline-inconsistent ART were examined by gender (). For WIHS women, having a higher HIV viral load at the previous study visit (OR=1.17, 95% CI 1.08, 1.27) was associated with a greater odds of reporting a guideline inconsistent regimen. Having a CD4 count ≥ 350 cells/mm3 measured at the prior study visit was associated with a 34% decrease in odds of reporting guideline-inconsistent ART (OR= 0.66, 95% CI 0.47, 0.94). After adjustment for age, race, insurance payor type, prescription drug coverage, prior visit CD4 count, and prior visit HIV viral load, only HIV viral load remained a significant predictor of a guideline-inconsistent regimen in WIHS women (aOR=1.16, 95% CI 1.05, 1.27).
Univariate and adjusted odds of reporting a guideline inconsistent antiretroviral regimen, by gender, the Women's Interagency HIV Study (WIHS) and the Multicenter AIDS Cohort Study (MACS), 2001–2007
For MACS men, higher HIV viral load at the prior study visit (OR=1.11, 95% CI 1.00, 1.23) was also associated with guideline inconsistent ART in univariate analyses (). A statistically significant association between having a higher HIV viral load and receipt of guideline-inconsistent ART remained (aOR=1.19, 95% CI 1.07, 1.34) after adjustment for age, race, insurance payor type, prescription drug coverage, and prior visit CD4 count.
In the analysis that included both men and women, gender was not associated with reporting guideline inconsistent ART in univariate or multivariate models (). Age greater than 50 years (OR=1.19, 95% CI 1.13, 3.32), moderate consumption of alcoholic beverages (OR=1.35, 95% CI 1.05, 1.74), and higher HIV viral load at the prior study visit (OR=1.13, 95% CI 1.06, 1.21) were linked to guideline inconsistent ART. After adjustment for gender, race, insurance payor, prescription drug coverage, and prior visit CD4 count, age over 50 (aOR=2.22, 95% CI 1.14, 4.33) and HIV viral load (aOR=1.17, 95% CI 1.09, 1.26) retained a statistically significant association with reporting guideline-inconsistent ART.
Factors associated with reporting guideline inconsistent antiretroviral therapy, the Women's Interagency HIV Study (WIHS) and the Multicenter AIDS Cohort Study (MACS), 2001–2007